Chapter 13 - Life in the Ocean

1. Chapter 13 - Life in the Ocean

2. characteristics of life require energy can capture, store, and transmit ultimately from sun, earth heat or chemical reactions highly ordered reproduce change through time adapt to environment

3. capture and flow of energy cell energy capture from sunlight from food

4. capture and flow of energy trophic relationships autotrophs primary producers convert energy to food heterotrophs consumers & decomposers consume food produced by others

5. capture and flow of energy depicting trophic relationships trophic levels food chain - simple food web - complex trophic pyramid

6. physical (abiotic) factors transparency dissolved nutrients temperature exothermic/poiklilothermic/cold-blooded endothermic/homeothermic/warm-blooded salinity extremes - 6 to 30 ppt

7. physical (abiotic) factors dissolved gases cold water holds more oxygen not easily dissolved avg - 6 ml/l plants use at night large blooms can result in low oxygen levels esp. in closed basins CO2 easily dissolved avg - 50 ml/l 60x that of the atmo. deep water has the most consumers downwelling cold water dissolving organisms

8. physical (abiotic) factors pH avg seawater is about 8 below CCD about 7.6 lowered by CO2 hydrostatic pressure animals equalize inside and outside pressure effects of high pressure gasses more soluble enzymes don’t work metabolic rates higher

9. physical (abiotic) factors factor interplay factors are interlinked also influenced by life

10. biotic factors diffusion tendancy of a concentration of a substance to even out from high concentration to low concentration faster in warm water across membranes

11. biotic factors osmosis diffusion of water through a semi-permeable membrane diffusion from high concentration of water to low concentration of water

12. biotic factors - osmosis isotonic concentration inside = concentration outside Some animals in ocean hypotonic concentration of salts inside > concentration of salts outside concentration of water inside < concentration of water outside marine animal in fresh water animal gains water hypertonic concentration of salts inside < concentration of salts outside concentration of water inside > concentration of water outside animal in Great Salt Lake freshwater and some marine animal in ocean animal loses water

13. biotic factors - osmosis examples and exceptions animal with salt concentration less than seawater drinks seawater cells lose water to even concentration in the blood animal dehydrates fish (?evolved in fresh water?) internal salinity 1/3 that of the ocean lose water through gills solution: drink seawater and excrete salts seabirds - excrete salt through glands in skull salmon - large kidneys remove excess water during freshwater phase of life, able to recover salts from food and urine

14. biotic factors active transport movement of dissolved substances from low concentration to high concentration requires energy

15. biotic factors surface-to-volume ratio smaller cells are more efficient at transport and diffusion spherical cell surface area increases with the square of its diameter volume increases with the cube of its diameter cells divide to maintain proper ratio

16. biotic factors gravity and bouyancy density differences water = 1 g/cm3 seawater = 1.025 g/cm3 marine fish = 1.07 g/cm3 adaptations gas bladders strong muscles less dense solutions in body ie.NH3Cl food stored in waxes and oils

17. biotic factors viscosity and movement reduce drag to swim increase drag to stop sinking large surface area to volume ratio ornamentation warm water less viscous than cold water movement use of currents to move

18. classification of environment light photic aphotic

19. classification of environment location pelagic - open water neritic - shallow oceanic - deep water epipelagic mesopelagic bathypelagic abyssopelagic benthic supralittoral - above the tidal range littoral sublittoral inner - near shore outer - to the edge of the shelf bathyal abyssal Hadal

20. Marine Communities organization organism population community ecosystem ecosphere

21. Marine Communities organism’s place habitat - organisms physical location within a community niche - organisms place (duties) within a habitat

22. Marine Communities physical and biological factors examples temp, pressure, salinity crowding, predation, grazing, parasitism, shading from light, waste substances, competition for resources (food, oxygen, nutrients) limiting factors limits chances for success different for different animals steno-: tolerant of a narrow range eury-: tolerant of a wide range

23. Marine Communities: competition within a species between species overlapping niches results survival and reproduction of the most successful less successful moves or dies off growth rate and carrying capacity

24. distribution of organisms population density species diversity distribution patterns random rare same conditions must exist throughout the community clustered most common individuals of a spies cluster near optimal conditions uniform - vary rare motile vs sessile

25. species interaction trophic symbiotic often species specific types mutualism commensalism - symbiont benefits, host is not harmed parasitism - host is harmed dependencies one species depends on another (for food) but they do not live in extended contact

26. change in marine communities usually slow marine conditions rarely change rapidly some rapid processes - volcanoes, earthquakes, landslides climax community stable long established reestablished through succession may be slightly different

27. evolution development of complex life forms through mutation and selection natural selection - survival of the fittest (for a niche) luckiest combination species reproductively isolated group of living organisms speciation & extinction divergent & convergent evolution phyletic gradualism & punctuated equilibrium

28. Organic evolution: observations sedimentary rocks deposited in layers oldest layers are on the bottom layers may be correlated with other sedimentary layers fossil record oldest rocks have only simple fossils younger rocks have more organisms similar to those living today (at levels from species to kingdom) fossils record includes appearances and extinctions of many species

29. Organic evolution: observations geographic distribution of organisms many organisms are similar but unique they are confined to specific areas (islands, continents, water bodies) includes modern and fossil organisms distribution has changed through time

30. Organic evolution: observations anatomy cell structure is similar in all living organisms embryology - embryos of mammals, birds, and reptiles are very similar homologus organs - similar organs, different functions vestigal organs - no purpose in one, purpose in another

31. Organic evolution: observations genetics structure of DNA and RNA is the same in all living organisms similarity in genetic code varies between organisms (some organisms are more similar than others)

32. Organic evolution: conclusions the characteristics of populations of living organisms have changed through time life has become more complex life has become more diverse this is excepted as a factual observation all life is related

33. Natural selection: observations populations of organisms display a variety of characteristics characteristics may be useful, not useful, or detrimental the variety is reflected in an organisms genes mutations produced by random alteration of genes and passed to offspring during reproduction provides variety

34. Natural selection: observations artificial selection domesticated plants and animals can be bred to favor certain characteristics populations of wild and domestic plants and animals develop characteristics that favor their survival

35. Natural selection: observations the natural environment organisms with favorable characteristics for their niche are more likely to thrive and reproduce organisms with unfavorable characteristics are less likely to thrive and reproduce a new niche or stress on an existing niche will enhance selection

36. Natural selection: conclusion the natural environment provides conditions that result in evolution through the process of natural selection

37. Evolutionary trends speciation & extinction divergent & convergent evolution phyletic gradualism & punctuated equilibrium

38. Natural selection: speciation a population has a gene pool members of the population interbreed the population may become isolated from others of a species development of niches & resource partitioning migration development of physical barriers populations may be selected by stress by opportunity isolation may result in genetic divergence

39. Natural selection: extinction stress on limiting factors reduce or destroy a population evolution into subsequent species (pseudo-extinction)

40. Phylogeny relationships between organisms can be determined using genetics anatomy & physiology Fossils

41. Evolutionary trends speciation & extinction divergent & convergent evolution phyletic gradualism & punctuated equilibrium

42. primary productivity photo- and chemo-synthesis

43. primary productivity measurement grams of carbon bound (appx 10% of producers mass) per square meter of ocean surface per year sampling measure oxygen produced in a suspended set of bottles follow carbon through the process (in the lab) breakdown phytoplankton - 90-98% seaweeds - 2-10% chemosynthesis - 1% production avg - 75 to 150 g(C)/m2/yr

44. primary productivity - limiting factors water - plenty CO2 - plenty nutrients non-conservative - change with bio activity nitrates, phosphates, silicates lost to organisms then to the depths replaced by runoff, upwelling, atmosphere

45. primary productivity - limiting factors light quantity - can have too much or too little quality - color red and violet are best absorbed by green quantity and quality vary with depth red is absorbed near the surface concentration of organisms concentration of sediment adaptations: accessory pigments - absorb light for chlorophyll

46. Plankton floaters and weak swimmers producers and consumers collection and study plankton nets microscopic

47. phytoplankton autotrophs depth of greatest productivity 20 m at noon 5-10 m daily compensation depth energy consumed = energy produced go below - die

48. global distribution of productivity near cont. shelves upwelling & runoff 1 g(C)/m2/day tropics much sunlight & CO2 low nutrients 30 g(C)/m2/yr reefs - tightly cycle nutrient through the reef - more productive polar low sun angle dark winter, long days in summer upwelling seasonal blooms temperate and subpolar good mix of light and nutrients seasonal

49. phytoplankton - dinoflagellates swim with whirling flagella reproduce through fission nutrients can causes blooms red tides some are bioluminescent

50. phytoplankton - diatoms SiO2 shell (frustule) two perforated valves highly energy efficient store energy as oils - for floating some are benthic reproduction fission - generate new shell inside the parent smaller with each generation size gets too small sexually reproduce new offspring with no shell

51. phytoplankton - nanoplankton very small coccolithopores - carbonate shells made of plates - chalk silicoflagellates

52. Plants vascular sap transport substances through vessels non-vascular algae “seaweed”

53. Plant structure problems shock abrasion water drag covered with a mucus-like substance lubricates retards drying deters grazers

54. Plant structure fluids algae - isotonic angiosperms - hypotonic thermal stress - heat speeds metabolic rate may not have enough oxygen available at night damages pigments anchorage/substrate algae - solid base rooted plants - unconsolidated base depth less than 2% of ocean floor is shallow enough

55. Plants - seaweeds thallus (plant) blade stipe gas bladder holdfast reproduction alternate sexual and asexual zonation: due to depth & other factors classification chlorophytes - green phaeophytes tan or brown kelp some are free-foating rhodophytes red most of world’s seaweeds

56. Plants - angiosperms flowering plants moved from land to water live at the surface structure leaves stem roots: extract nutrients from the substrate types sea grasses mangroves

57. animals - classification artificial systems exterior similarities functions, colors, etc. natural systems originally based on structural and biochemical similarities now based on DNA Linnaeus K, P, sub-P, C, O, F, G, S scientific name genus-species permanent unchanging words - usually Latin internationally monitored

58. animals - key events oxygen in the ocean and atmosphere 2 BYA - 1% oxygen 400 MYA - 20% oxygen thanks to photsynthetic oxygen metazoans - multi-cellular soft-bodies - first appx. 600 MYA Ediacara Hills, Aust. bizzare segmented worms shelled animals - first appx. 550 MYA arthropods - trilobites

59. zooplankton consumers most animal groups represented create oxygen minimum zone just below the well-lighted surface zone size most less than 1 cm some > 1 cm - macroplankton life cycle holoplankton - spend entire lives as plankton meroplankton - spend part of life as plankton

60. Protista (zooplankton) foraminifera amoeba-like carbonate shells radiolarians amoeba-like spike-like pseudopods amoebas

61. P. Porifera sponges suspension feeders structure collar cells - capture and digest amoeboid cells - transport food surface cells - protect spicules and spongin - support

62. P. Cnidaria jellyfish, anemones, corals radial symmetry structure stinging cells - capture food, repel predators some nerve cells mouth/anus digestive cavity form - polyp or medusa

63. P. Platyhelminthes flat worms - tape worms parasitic & free-living bilateral symmetry structure mouth/anus nervous system, brian, eyespots no resp or excret systems

64. P. Nematoda roundworms structure flow-through digestive system important sediment-feeders

65. P. Annelida segmented worms structure head flow-through digest segment with circ, excret, nerv, musc, repro systems

66. P. Mollusca characteristics soft body most have a shell bilateral symmetry flow-through digest circ, excret, nerv, musc, repro systems classes polyplacophora gastropoda bivalvia cephalopoda

67. P. Arthropoda characteristics exoskeleton must molt to grow striated muscle articulated classes insecta - poorly represented at sea Crustacea crabs, krill, lobsters, barnacles copepods zooplankton crustaceans 70% of animals

68. P. Echinodermata five-way symmetry start as bilaterally symmetrical classes asteroidea - sea stars tube feet water vascular system - locomotion & feeding ophiuroidea - brittle stars widely distributed echinoidea - sea urchins and sand dollars holothuriodea - sea cucumbers

69. other Phyla Bryozoa - important ancient reef builders Brachiopoda - very important bivalved shell animals in the Paleozoic Hemichordata - important transitional phyla

70. P. Chordata invert tunicates - suspension feeders lancelets example: amphioxis transitional species

71. Fish (vertebrates) agantha jawless fishes lampreys, hagfish condrichthyes cartiliginous fishes sharks, skates, rays, chimera

72. Fish (vertebrates) osteichthyes - bony fishes shape - antidrag movement - eel-like or hinged-tail maintenance of level - swimming or gas bladder gas exchange - gill membranes osmotic problems (advanced fish) - hypotonic (lose water) - drink water & excrete salt - conservative kidneys feeding & defense - sight, hearing (inc. lateral line), coloration (cryptic coloring and top/bottom counter-shading), schooling

73. amphibians none exclusively marine adapted to land and freshwater permeable skin

74. reptiles characterisics lungs scales salt glands groups sea turtles 8 species all endangered streamlined shells, flippered feet marine crocodiles - one species, in tropical W Pacific marine lizards - only Galapagos marine iguana sea snakes 50 known species highly venomous

75. birds sea birds - 270 species warm-blooded characteristics salt-excreting glands avoid land except for breeding obtain almost all food from the sea groups Tubenoses - albatrosses & petrels pelicans et. al. gulls & puffins penguins

76. mammals characteristics of marine mammals streamlined warm-blooded resp. system modified to collect and retain large quantities of oxygen

77. Mammal orders cetacea evolved from early ungulates (horses and sheep) horizontal tail flukes that move up and down toothed whales - orca, dolphins, porpoises - echo location baleen whales - filter-feeders carnivora pinnipedia - seals, sea lions, walruses fissipedia - sea otters, polar bears sirenia - mantees

78. rocky intertidal problems wave shock wetting and drying land and water predators daily and annual sediment movement benefits lots of food stirred up food and gasses many niches very diverse zoned

79. sand and cobble beaches problems as above loose bottom moving sand abrasive mixed with food much less habitable

80. salt marshes and estuaries salinity can vary greatly salty - brackish - fresh vertically and horizontally leads to complex zonation isolation at low tide raises salinity raises temp estuaries highly diverse and productive marine nurseries

81. open ocean top 200 meters 83% of biomass almost all productivity deep scattering layer top of the dark zone move up to feed at night can see shadows of prey above may have light organs to mask own shadow bathypelagic little food available bizarre animals little known

82. deep sea floor dark cold slightly hyper saline weak currents organisms blind many scavangers, some predators low metabolic rate may eat less than once per year may live to be 100 large fragile

83. vent communities discovered in 1977 chemosynthetic producers superhot water (350EC) some animals (tube worms, clams) house chemosynthetic bacteria for food

84. reefs materials are tightly cycled corals other animals types fringing barrier atolls